[The x club is probably unique in the smallness of its numbers, the intellectual eminence of its members, and the length of its unchanged existence. The nearest parallel is to be found in "The Club." (Of which Huxley was elected a member in 1884. Tyndall and Hooker were also members.) Like the x, "The Club" began with eight members at its first meeting, and of the original members Johnson lived twenty years, Reynolds twenty-eight, Burke thirty-three, and Bennet Langton thirty-seven. But the ranks were earlier broken. Within ten years Goldsmith died, and he was followed in a twelvemonth by Nugent, and five years later by Beauclerk and Chamier. Moreover, the eight were soon increased to twelve; then to twenty and finally to forty, while the gaps were filled up as they occurred. In the x, on the contrary, nearly nineteen years passed before the original circle was broken by the death of Spottiswoode. From 1864 to Spottiswoode's death in 1883 the original circle remained unbroken; the meetings "were steadily continued for some twenty years, before our ranks began to thin; and one by one, geistige Naturen such as those for which the poet so willingly paid the ferryman, silent but not unregarded, took the vacated places." (Nimm dann Fuhrmann, Nimm die Miethe Die Ich gerne dreifach biete; Zwei, die eben uberfuhren Waren geistige Naturen.) The peculiar constitution of the club scarcely seemed to admit of new members; not, at all events, without altering the unique relation of friendship joined to common experience of struggle and success which had lasted so long. After the death of Spottiswoode and Busk, and the ill-health of other members, the election of new members was indeed mooted, but the proposal was ultimately negatived. Huxley's opinion on this point appears from letters to Sir E. Frankland in 1886 and to Sir J.D. Hooker in 1888.] As for the filling up the vacancies in the x, I am disposed to take Tyndall's view of the matter. Our little club had no very definite object beyond preventing a few men who were united by strong personal sympathies from drifting apart by the pressure of busy lives. Nobody could have foreseen or expected twenty odd years ago when we first met, that we were destined to play the parts we have since played, and it is in the nature of things impossible that any of the new members proposed (much as we may like and respect them all), can carry on the work which has so strangely fallen to us. An axe with a new head and a new handle may be the same axe in one sense, but it is not the familiar friend with which one has cut one's way through wood and brier. [And in the other letter:--]